Fuel supply system



Jan. 26, 1937- H. A. HANSEN 2,068,951

rp-EL SUPPLY SYSTEM Filed Nov. 2, 1932 zlsheets-sheet 1 mmv rok H. fi/berf Hansen ATTORNEY Jan--26, 1937.. H. A. HANSEN 2,068,951

v FUEL SUPPLY SYSTEM Fild Nov. 2, 1952 2 Sheets-Sheet 2 \J a3 a4 84 g I a2,

85 82 INVENTOR.

- H. fl/berf Hansen BY .Wu

ATTO EY Patented Jan. 26, 1937 PATENT OFFICE FUEL SUPPLY SYSTEM Hans Albert Hansen, South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application November 2, 1932, Serial No. 640,896 6Claims. (01.123-142) This invention relates to a vapor-tight system of carburetion and fuel supply and is illustrated as applied to a gasoline engine in a marine installation. p In power boats utilizing internal combustion engines, it is common to enclose the engine in a compartment by itself which is substantially airtight as far as ventilating drafts are concerned,

and which is also water-tight so as to avoid the possibility of heavy seas short circuting the ignition. Such practice, however, produces a fire hazard since the atmosphere surrounding interventilated engine compartment, and further toprevent the escape of any flame from back fire in the engine compartment.

25 Accordingly, it is an object of this invention to provide a marine engine with a fuel supply system which will prevent combustible vapors escaping therefrom.

A further object of the invention is to provide 30 enclosed overflow receptacles which may be emptied by the suction'of the engine.

A further object of the invention is the provision of an enclosed fuel supply system, wherein manifold suction is adapted to draw ofi gasoline 0 liquid or vapors at such points as they may tend to escape from the system.

A further object is the provision of mechanism whereby the engine intake may draw air from within the engine compartment, but upon back fire, is instantaneously connected to outside atmosphere and sealed against leaks within the compartment.

A still further object is the provision of means for coupling the carburetor air intake outside the engine compartment at all times except during normal running to prevent any explosion or back fire escaping in the event of engine back firing.

' Another object is the provision of means for coupling the carburetor air intake outside the engine compartment and at the same time for preventing the entrance of water into the intake.

Still another object is to provide a marine engine with a carbureting system which will prevent flames or combustible vapors from escaping 55 into the surrounding compartment when the engine backfires, and yet permit the engine to draw the air necessary for carburetion from the engine compartment during normal operation.

The above and other novel features of the invention will appear more fully hereinafter from the following detailed description when taken in conjunction with the accompanying drawings. It is expressly understood, however, that the drawings are employed for purposes of illustration only and are not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawings wherein similar reference characters refer to similar parts:

Figure 1 illustrates a side elevation partly in section of a vapor-tight fuel supply system as applied to a marine engine installation;

Figure 2 is a side elevation of a preferred form of back fire valve readily adaptable to the system of Figure 1;

operating position, as in back fire, or when not operating.

Referring more particularly to Figure l of the drawings, it will be seen that the internal combustion engine I0 is located beneath the deck l2 or top of the engine compartment as the case may be, and is provided with an intake manifold II and carburetor l6. Connected to the float chamber l8 of the carburetor I6 is the usual gasoline pipe leading from the fuel tank through some kind of supply system such as a fuel pump 22, if the system be other than gravity. The top of the fuel tank is preferably provided with a filler opening connected by means of an air-tight flexible tubing 26 to a filler fitting 21 provided with a cap 30 located in the compartment top. or deck I2.

I Within the flexible tubing 26 is positioned a tube 28 extending close to the bottom of the fuel tank 24 having a flange 29 at the upper end thereof adapted to seat on an annular shoulder 3| within the fitting 21. A vent 32 also extendingirom the top of the tank passes through thecompartment top or deck so that vapors passing therethrough may be vented outside of the compartment at any suitable or safe point, while a shield it prevents the inflow of foreign matter such as dirt, water,

etc.

Since for proper operation of the carburetor float valve the float chamber It must be vented to atmosphere, and in order to prevent the escape of these vapors into the engine compartment, the vent is connected preferably to the air horn 36 of the carburetor by a suitable connecting tube 34.

By means of the flexible tubing 38 and vaportight pipe connections 40, the air intake of the carburetor is connected with the outside of the engine compartment, so that back firing through the carburetor intake passages will not fill the compartment with unburnt gases, nor ignite inflammable vapors lurlnng in the compartment due to some unforeseen leak. I

In order to prevent water from entering the carburetor air intake, a water separator may be provided as shown at 42, (see Fig. 1) comprising an air entrance duct 44 extending to outside atmosphere, and an air outlet duct 46 connected to the air intake pipe 40, tube 38 and carburetor IS. The air inlet duct is so arranged within the separator that the direct inflow of air therefrom may not enter the air outlet, so that any water by reason of its weight and inertia, will be driven to a part away from the air outlet.

Suitable guards such as 48 may be provided on the outlet duct 48 to protect against splash within the separator, should it momentarily be filled and shaken up as might occur in heavy seas. At the bottom of the separator is provided a drain pipe 50 connected constantly to the separator through small apertures 52, which are normally sufficient in size to permit adequate draining. Under abnormal conditions, the float 54 fixed to the guide rod 58 by the grids 56 and 66, will rise due to collection of water in the separator and leave the drain pipe 50 unobstructed for quick relief. To insure against the escape of vapors through the drain, should the same drain into the bilge, a trap such as 53 may be provided to form a perfect seal.

The water separator illustrated in Figure 1, although adequate in preventing spray from entering the intake manifold, may prove inadequate unless constructed relatively large to take care of water in large quantities, since the quantity of air required to supply an internal combustion engine is necessarily great, should the air inlet be submerged temporarily, the air supply would be cut ofl. Accordingly, where heavy seas are to be encountered, it is advisable to provide a construction such as shown in Figure 2 wherein there is provided a mechanism whereby the internal combustion engine may draw air from within the engine compartment while normally running, but which is adapted to 'be instantaneously cut off from the compartment and connected with the outside in the event of back fire or during such time as the engine is not in operation.

To accomplish this result the air intake 16 is connected to a back fire bypass valve 84 located at a convenient point in the engine compartment preferably near the ceiling. The intake pipe it is connected to the channel 16, as shown, which is protected by a dust cover 75 but otherwise open to the engine compartment except for the butterfly valve Ti. A second channel 18 preferably arranged parallel to the channel M is connected to a duct 'lfi'leading outside the engine compartment, which may be protected by aclamshell or cowl ventilator, as at 85. The lower end of the channel 18 is connected by the pipe 82 to the drain, and is preferably provided with a water trap, as shown in Figure 1. A bypass channel 83 connects the intake channel 14 and the atmosphere channel 18 and is inclined so as to prevent flow of water into the intake channel. To positively cut off communication outside the compartment, a butterfly bypass valve 84 is provided in the inclined channel 83, and is preferably so designed as to deflect water entering channel into the drain when in open position.

As shown in Figure 2, the valves 11 and-8| a interconnected by means of cranks 86 and 88, and the link 89, and are adapted to be operated simultaneously by the linkage 92 and suction motor 90 which is connected to the internal combustion engine intake manifold by a tube 94.

To take care of the fuel which accumulates in the carburetor air inlet and in the intake manifold during the starting of the engine, a container 62 (Figure 1) is preferably connected to the lowest point in the carburetor air horn by means of a pipe 64 and into which the overflow may run. To withdraw this overflow, a connection may be made by a pipe 66 to the manifold 14 whereby the fluid may be drawn off, and to prevent excess air bleed into the intake manifold when container 62 is empty the pipe 66 or one of its fittings is preferably constricted at one point, which merely has the effect of slowing up the rate of drawing fuel from the container. This is desirable since the discharge ,of excess fuel into the manifold is gradual and does not momentarily too greatly enrich the mixture.

In operation, air entering the duct 44 with water is re-directed to the outlet duct 46, the water separating itself by gravity or inertia from the air stream. Excess fuel from the carburetor and manifold is caught in the overflow container 62 from which, when the engine is running, it is drawn into the manifold. Venting of the float chamber during running is accomplished by the connection to the air horn or intake pipe through the connection 36.

The back fire valve illustrated in Figure 2, which may be used in place of the water separator of Figure l, is shown in closed position, the valves being arranged as shown in detail in Figure 4:. With the valves in this position, the carburetor air intake is completely out off from the engine compartment by the valve 17 and is connected to outside atmosphere through the bypass valve 84. As the engine starts, the suction motor, due to vacuum derived from the engine manifold, raises the linkage 92 and opens valve 77 and closes valve 84 to the positions shown in Figure 3. Should the engine back-fire, the absolute pressure in the intake manifold is instantaneously increased with the result that the suction motor closes and opens bypass valve 84 allowing the back fire products to escape outside. Such an arrangement permits the consumption of air within the engine compartment with safety, which consumption is desirable from the standpoint of aiding ventilation of the engine compartment and at the same time there is provided a means for preventing the .escape of back fire flames within the compartment.

There is thus provided a vapor tight system of carburetion and fuel supply readily adaptable to stationary or marine internal combustion engine installations and wherein dangers resulting from back firing and the leakage of fuel vapors in the immediate vicinity of the engine are completely eliminated.

Though several embodiments or modifications of the invention have been illustrated and described, it is to be understood that the invention is not limited thereto but may be embodied in various modifications and arrangeinents'which may be made without departing from the spirit of the invention, as will be apparent to those skilled in the art. Accordingly, reference will be had to with a source of air adapted for carburetion pur- 1 the appended claims for a definition of the limits of the invention.

What is claimed is: I

1. A back fire-valve comprising a connection to an internal combustion engine intake, an intake port, and a back fire exhaust port, a valve operable by a suction motor connected with the engine intake, at a point near said engine, said valve adapted to connect said intake port with said engine intake at such times as suction exists.

2. A back fire valve comprising an engine intake connection, an air intake, and a back fire by-pass port, valve means adapted to shift said engine intake connection between said air intake and said by-pass port, and an engine manifold suction operated means for normally shifting said valve to connect said engine intake to the air intake. 3. An internal combustion engine, a carburetor system including an intake manifold, and a carburetor intake, a source of air for normal running, a by-pass connection for abnormal operation, means controllable 'by the pressure conditions in the manifold for shifting said intake from said source of air to said by-pass connection.

4. An internal combustion engine air intake connection, a two-way valve, one way connected poses, the other way adapted to connect .to a

second body of air into which exhaust gases may escape, and suction means for shifting said valve to the second body of air upon engine backfire.

5. In a carburetion system for an enclosed internal combustion, engine having an intake manifold, an air inlet passage having two branches, one leading from within the enclosure, the other leading from without the enclosure, a pressure operated motor connected with the manifold, and

, means including interconnected valves in said branches operable by said motor to admit air to the carburetor through one branch under normal operating conditions and to discharge gases through the other branch-upon a substantial rise in pressure in the manifold. v

6. In a carburetion system for an enclosed in ternal combustion engine having asource of differential fluid pressure, an air inlet passage leading from within the enclosure, 9. second air inlet passage leading from without the enclosure, 7

a pressure operated motor actuated by said differential fluid pressure, and means including a plurality of interconnected valves positioned in said air inlet passages and operable by said motor to selectively connect the carburetor with different air inlet passages. I

H. ALBERT HANSEN. 

